1. Field of the Invention
Embodiments of the invention relate to in-band signaling to indicate an end of incoming stream of data for real-time, or near real-time and user-context update.
2. Description of the Related Art
Wireless communication systems have developed through various generations, including a first-generation analog wireless phone service (1G), a second-generation (2G) digital wireless phone service (including interim 2.5G and 2.75G networks) and a third-generation (3G) high speed data/Internet-capable wireless service. There are presently many different types of wireless communication systems in use, including Cellular and Personal Communications Service (PCS) systems. Examples of known cellular systems include the cellular Analog Advanced Mobile Phone System (AMPS), and digital cellular systems based on Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), the Global System for Mobile access (GSM) variation of TDMA, and newer hybrid digital communication systems using both TDMA and CDMA technologies.
The method for providing CDMA mobile communications was standardized in the United States by the Telecommunications Industry Association/Electronic Industries Association in TIA/EIA/IS-95-A entitled “Mobile Station-Base Station Compatibility Standard for Dual-Mode Wideband Spread Spectrum Cellular System,” referred to herein as IS-95. Combined AMPS & CDMA systems are described in TIA/EIA Standard IS-98. Other communications systems are described in the IMT-2000/UM, or International Mobile Telecommunications System 2000/Universal Mobile Telecommunications System, standards covering what are referred to as wideband CDMA (W-CDMA), CDMA2000 (such as CDMA2000 1xEV-DO standards, for example) or TD-SCDMA.
In W-CDMA wireless communication systems, user equipments (UEs) receive signals from fixed position Node Bs (also referred to as cell sites or cells) that support communication links or service within particular geographic regions adjacent to or surrounding the base stations. Node Bs provide entry points to an access network (AN)/radio access network (RAN), which is generally a packet data network using standard Internet Engineering Task Force (IETF) based protocols that support methods for differentiating traffic based on Quality of Service (QoS) requirements. Therefore, the Node Bs generally interact with UEs through an over the air interface and with the RAN through Internet Protocol (IP) network data packets.
In wireless telecommunication systems, Push-to-Talk (PTT) capabilities are popular with service sectors and consumers. PTT can support a “dispatch” voice service that operates over standard commercial wireless infrastructures, such as W-CDMA, CDMA, FDMA, TDMA, GSM, etc. In a dispatch model, communication between endpoints (e.g., UEs) occurs within virtual groups, wherein the voice of one “talker” is transmitted to one or more “listeners.” A single instance of this type of communication is commonly referred to as a dispatch call, or simply a PTT call. A PTT call is an instantiation of a group, which defines the characteristics of a call. A group in essence is defined by a member list and associated information, such as group name or group identification.
Applications, which are receiving one or more incoming streams of data (e.g., audio, video, etc), need to update a user context when the steam of data ends. Some applications may have real-time (e.g., minimum latency) requirements for the user context update, and therefore these applications require precise and instantaneous knowledge regarding when the stream of data ends. Conventionally, the end of the stream of data can be inferred after a period of traffic inactivity, or can be expressly indicated via the use of out-of-band signaling (e.g., via an “END” signal). Generally, out-of-band signaling can be delayed and can be complex to implement. Also, relying on out-of-band signaling for indicating the end of a stream of data may leave a gap in time where the “END” signal arrives either too early or too late, which results in the possibility of truncating the stream short (e.g., if “END” signal arrives early) or permitting the stream to continue in a starved mode (e.g., if “END” signal arrives late, such that RTP packets stop arriving but there is no user-context update).
In addition, the use of inactivity timers involves updating the user context after a threshold period where no streaming packets associated with the stream of data are received. Inferring the end of a session based on an inactivity timer can be difficult because the inactivity timer must accommodate temporary network disruptions as well as actual stream termination, and a single timer value is unlikely to be appropriate for both scenarios.